N4352YPiper PA-25-235 · 1968

On May 5, 2008, at 1734 central daylight time, a Piper PA-25-235 Pawnee, N4352Y, operated by a commercial pilot, was substantially damaged when it impacted trees and terrain while maneuvering during an aerial application flight near New Lisbon, Wisconsin. Visual meteorological conditions prevailed at the time of the accident. The flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 137 without a flight plan. The pilot was fatally injured. The local area flight departed a private airstrip near New Lisbon, Wisconsin, about 1730, and was applying dry fertilizer at the time of the accident.

A witness reported that the airplane made several low altitude passes over a nearby agricultural field. After the final pass, he lost sight of the airplane shortly after it climbed over a tree line situated at the southeast corner of the field. He then noted a decrease in engine noise, which was immediately followed by two loud "crashing" sounds.

Another witness was driving south on Wisconsin State Highway 80 when he saw the accident airplane emerge from over a tree line ahead of his position. The airplane was low and "turned perpendicular to the ground" in a steep left turn to the west. He lost sight of the airplane after it descended into the trees.

According to Federal Aviation Administration (FAA) records, the pilot of N4352Y, age 55, held a commercial pilot certificate with an airplane single-engine land rating. He was not instrument rated. The pilot's last aviation medical examination was completed on March 10, 2008, when he was issued a second-class medical certificate with the limitation that he wear corrective lenses. At the time of the medical examination, the pilot reported having 10,384 hours of flight experience, of which 150 hours were flown during the past 6 months. A search of FAA records showed no accident, incident, enforcement or disciplinary actions.

The pilot's most recent logbook entry was flight review dated April 3, 2008. As of this entry, he had accumulated 10,323.4 hours total flight time, of which 10,146.4 hours were as pilot-in-command. All of his flight experience was in single-engine land airplanes. He had accumulated 180.2 hours at night and 11.9 hours in simulated instrument conditions.

The accident airplane was a 1968 Piper PA-25-235 Pawnee, serial number (s/n) 25-4852. The airplane incorporated a steel-tube-truss design with fabric covering. It was equipped with externally braced wings, wing flaps, and a fixed conventional landing gear. The airplane seated a single occupant and had a certified maximum takeoff weight of 2,900 lbs.

The airplane was issued a restricted airworthiness certificate on January 3, 1969. The airplane was owned and operated by Kaz's Flying Service, Ltd., an aerial application company. The airframe had a total service time of 9,652.6 hours at the time of the accident. The last annual inspection was completed on May 17, 2007, at 9,246.7 hours total service time. The last maintenance performed on the airframe was on May 3, 2008, when the airplane was equipped with a horizontal stabilizer support kit.

A Lycoming model O-540-B2C5 reciprocating engine, s/n L-14937-40, powered the airplane. The 235-horsepower engine provided thrust through a McCauley model 1A200, s/n 104997, fixed pitch, two-blade, metal propeller. The engine had accumulated 1,398.1 hours since its last major overhaul. The last maintenance performed on the engine was on July 10, 2007, when new sparkplugs were installed.

A review of the airframe, engine and propeller records found no history of unresolved airworthiness issues.

The closest weather station to the accident site was at Volk Field Airport (KVOK), Camp Douglas, Wisconsin, located about 6 nautical miles northwest of the accident site. The airport was equipped with an automated surface observing system (ASOS).

At 1655, the KVOK ASOS reported the following weather conditions: Wind 330 degrees true at 8 knots; visibility 10 miles; sky overcast at 10,000 feet above ground level; temperature 20 degrees Celsius; dew point 1 degrees Celsius; altimeter setting 29.98 inches of mercury.

The accident site was located in a wooded area situated to the east of field being sprayed. The debris path, from the initial tree strike to the main wreckage, was approximately 200 feet long and was oriented on a 350-degree magnetic bearing. The tree line was approximately 70 feet high. Several tree limbs, which exhibited fresh breaks, were observed along the debris path. The left wing had separated from the fuselage and was located about 15 feet above the ground amongst several trees. The main wreckage consisted of the entire fuselage structure, empennage, right wing, engine and propeller. The fuselage came to rest inverted, immediately adjacent to an access road. There was no evidence of fire. All flight control surfaces were accounted for at the accident site. All control cable separations were consistent with tensile overload failure.

The engine remained partially attached to the airframe. The engine was rotated by turning the propeller flange. Crankshaft continuity was confirmed to all engine cylinders, rear gear assemblies, and the valve train. All six cylinders exhibited compression during crankshaft rotation. No anomalies were noted with either magneto. The magneto equipped with an impulse coupling provided spark when rotated. Both propeller blades exhibited blade twist, spanwise bending, chordwise scratching, and leading edge damage.

Examination of the airframe, engine and propeller did not reveal any anomalies associated with a pre-impact failure or malfunction.

On May 7, 2008, an autopsy was performed on the pilot at the Hess Memorial Hospital in Mauston, Wisconsin. The cause of death was attributed to "multiple injuries due to a plane crash."

The FAA's Civil Aeromedical Institute in Oklahoma City, Oklahoma, performed toxicology tests on the pilot. No carbon monoxide or cyanide was detected in blood, no ethanol was detected in vitreous, and no drugs were detected in urine.